Heating of liquid pharmaceutical products (from herein referred to as “products”) prior to administration is often required to increase the solubility of the active ingredients in these products. With specific regard to parenteral products, especially veterinary parenteral products, heating can also reduce the potential for systemic cold-shock to the patient upon administration of the product.
These products can often be administered in remote, exposed and cold conditions e.g. in fields where animals need to be treated. Therefore heating or resolubilisation of the product constituents is often carried out by shaking and rolling between the users hands or even using heating jackets around the bottle or container that require an external energy supply like a battery or sunlight. A considerable amount of energy and time can be expended trying to heat the liquid formulations to the required temperature. This problem is compounded by the volume of the bottles being in the range of 2000 to 100 ml in order to provide doses to a plurality of patients or animals as well as the fact that glass or plastic bottles several millimetres thick are routinely used as product packaging. Furthermore, many products for veterinary use are extremely viscous at e.g. about 50-500 cP at about 4° C.
Additionally such products, especially parenteral products, are commonly encased in protection chambers to minimise breakage. It is clearly not desirable to have yet another device in addition to the protection chamber for the user to handle prior to administration of the product. Therefore it is desirable to have a device that allows the user of the product to heat products without having to remove the product from the protection chamber.
Some heating devices for warming IV infusion products for administration to humans are known. For example, GB 2248106 and U.S. Pat. No. 4,934,336 show flexible insulating packs with warming devices for heating bags of fluid for IV infusion. However, the fluid is typically a liquid of very low viscosity compared with typical veterinary products, and it is contained within a thin-walled plastic bag. Such devices are therefore unsuitable for highly viscous veterinary products contained in comparatively thick-walled glass containers, because insufficient heating and protection against breakage is provided.
WO 2005/056089 describes a heating device for a rigid container of fluid, but the casing has extremely thick walls, making it heavy and bulky, and it requires an external power supply for heating. It is therefore entirely unsuitable for veterinary use where portability is essential.